Water pollution caused by processing solutions in the processing of silver halide color photographic materials is presently a most important problem needing to be solved.
On the other hand, there is a demand for the shortening of processing time in order to provide rapid processing services to customers.
Iron(III) complex salts of aminopolycarboxylic acids, such as, iron(III) complex salts of ethylenediaminetetraacetic acid, and diethylenetriaminepentaacetic acid are used as bleaching agents in bleaching solutions and in bleaching-fixing solutions having the ability to bleach. The concentrations of the complex salts are usually 0.25 to 0.5 mol/l when color photographic materials are processed.
The discharge of such soluble salts, as mentioned above, is restrained in many water areas, because of the coloration of water, etc.
The decomposition speed of ethylenediaminetetraacetic acid by microorganisms in the natural environment is slow. For this reason, the discharge of this compound is restrained in some water areas in Europe. Accordingly, great care is taken in the art to reduce the discharged amounts of the iron(III) complex salts of the aminopolycarboxylic acids.
Attempts have been made to reduce the discharge amounts thereof. For example, methods have been proposed wherein:
the replenishment rates of processing solutions are reduced; PA1 the waste liquors of the processing solutions are reclaimed or regenerated and reused; PA1 the concentrations of the iron(III) complex salts of the aminopolycarboxylic acids are reduced; and PA1 combinations of the foregoing methods.
Among the above methods, the reduction of the concentrations of the iron(III) complex salts of the aminopolycarboxylic acids in the processing solutions having bleaching ability is more effective in comparison with any combination of the other methods, and considered to be the most basic method.
From this standpoint, the present inventors have made studies to reduce the concentrations of the iron(III) complex salts of conventional aminopolycarboxylic acids, such as, iron(III) complex salts of ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, 1,3-diaminopropanetetraacetic acid, and cyclohexanediaminetetraacetic acid. It has been found that, when the concentrations of any of the above iron (III) complex salts are lowered, lower bleaching performance results, and the lowering of bleaching performance is remarkable particularly when color light-sensitive materials containing silver halide emulsions comprising tabular silver iodobromide grains are processed; it has also been found that when the concentrations of the above iron(III) complex salts are lowered, it is also difficult to conduct bleaching in a short period of time. Further, the present inventors have found that when the concentrations of the iron(III) complex salts of the aminopolycarboxylic acids are reduced to 0.2 mol/l or lower, the bleaching of the developed silver of tabular silver iodobromide grains is extremely deteriorated, and a failure in desilverization is caused. Furthermore, it has been found that a failure in the restoration of cyan dye is also liable to be caused.
Tabular silver iodobromide grains can improve sensitivity without detriment to image quality. The details thereof are described in Research Disclosure 22534, and tabular silver iodobromide grains have been widely used practically in high-sensitivity color negative films in recent years.
U.S. Pat. No. 4,552,834, JP-A-61-17143 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"), JP-A-62-91953 and JP-A-2-46448 disclose that when emulsions comprising tabular silver iodobromide grains having a high aspect ratio are coated, the bleaching of the resulting color light-sensitive materials is made difficult. These references further disclose that this difficulty is mainly due to the fact that a large amount of sensitizing dye deposited on the tabular silver iodobromide grains and interferes with the bleaching reaction.
To solve the above-described problem, there have been proposed aromatic amine bleaching accelerators, such as, 1,3-phenylenediaminebis(2,2'-iminodiethanol), in the aforesaid U.S. Patent; bleaching-fixing solutions containing (ethylenediaminetetraacetato)iron(III) complex salts in JP-A-61-17143; the use of a combination of a bath having a bleaching ability with a bath having a bleaching-fixing ability, in JP-A-62-91953; and bleaching baths containing (1,3-diaminopropanetetraacetato)iron(III) complex salts or (1,4-diaminobutanetetraacetato)iron(III) complex salts as bleaching agents in an amount of at least 0.2 mol/l, in JP-A-2-46448 and JP-A-4-43347.
Further, Research Disclosure 24241, ibid. 11449 and JP-A-61-201247 disclose that bleach accelerating compound-releasing couplers contribute to the improvement of bleaching performance.
These methods certainly have the effect of improving the bleaching of the emulsions comprising tabular silver iodobromide grains. However, it is not considered that the above-described problem can be fully solved by such methods, and these methods are particularly ineffective in reducing the concentrations of the bleaching agents.
Specifically, the present inventors have found that even when the foregoing methods are carried out, the reduction in the concentrations of the iron(III) complex salts of the aminopolycarboxylic acids causes a lowering in the bleaching performance, and failure in the restoration of cyan dye.